1. Technical Field
The present invention relates to vertically integrated optical components, and in particular to a process for making simultaneously a plurality of vertically integrated optical components which combines the manufacture of ultrathin polarizing glass and attachment of polarizer devices made from ultrathin polarizing glass to optical fibers.
2. Description of Related Art
The use of very thin polarizing glass devices makes it possible to produce optical components without the need for expensive lens elements and more importantly, lessen alignment problems in order to maintain high light throughput. Very thin polarizers can replace lens elements which collimate and refocus the light which exits and re-enters the optical fibers carrying the signal. Very thin polarizers are required, however, preferably around 30 xcexcm, to shorten the optical pathlength to decrease diffraction losses. These, and other aspects of vertical integration technology are described by Shiraishi et al., in xe2x80x9cVertical Integration Technology for Fiber-Optic Circuitxe2x80x9d, Optoelectronics, Vol. 10, No. 1, pp. 55-74, March 1995.
An example of a polarizing glass, POLARCOR(trademark) is available from Corning Incorporated, Corning, NY. This product is available in planar shapes with dimensions up to 30 mm parallel to the major principal transmission direction. POLARCOR(trademark) products are also available in thickness as low as 200 xcexcm.
U.S. Pat. Nos. 3,325,299, 4,479,819, 5,430,573, 5,322,819, 5,300,465, 5,281,562, 5,275,979, 5,045,509, JP 4-279337, JP 5-208844 and EP 0719 741 all describe glass articles which are polarizing in the infrared region. JP 4-279337 and JP 5-208844 describe a copper-based polarizing glass which, according to the patent application can measure less than 240 xcexcm in thickness. However, the examples were limited to glass thickness in the range of 100 to 1000 xcexcm.
PCT Application Serial No. PCT/US99/07521 entitled xe2x80x9cUltrathin Glass Polarizers and Method of Making Samexe2x80x9d, having as inventors Borrelli et al., assigned to the instant assignee, discloses a process by which polarizing glass can be thinned down to form an ultrathin polarizing glass measuring less than 50 xcexcm, preferably between about 10-40 xcexcm.
However, even with the attainment of ultrathin polarizing glass devices there exits the difficulty of attaching these devices to optical fibers. Conventionally, attachment is performed manually by individually attaching each polarizing device to an optical fiber endface. This manual process is not only labor-intensive and inefficient, but also costlyxe2x80x94costs which are ultimately translated to the end consumer. Further, there is extensive manipulation of the polarizing glass devices and optical fibers, which increases the possibility of contamination and damage.
Therefore, there exists the need for a process which simplifies both the manufacture ultrathin polarizing glass and attachment of polarizer devices made from ultrathin polarizing glass to optical fibers in the formation of vertically integrated optical components.
Accordingly, it is an object of the present invention to reduce and eliminate the above-mentioned difficulties by providing an approach which combines the manufacture and the attachment of polarizer devices made from ultrathin polarizing glass to optical fibers. It is a further object of the present invention to provide a process that is expedient and cost-efficient by incorporating mass-production techniques.
Other objects and advantages of the present invention will be apparent from the following description.
In accordance with the present invention, there is provided a process for making simultaneously a plurality of vertically integrated optical components which combines the manufacture and attachment of polarizer devices made from ultrathin polarizing glass to optical fibers. In one embodiment of the present invention the process comprises the steps of:
providing a holding device having a plurality of holes for receiving a plurality of optical fibers insulated by ferrules,
providing a polarizing glass comprising a first polarization layer and a second polarization layer, where the first polarization layer and the second polarization layer are separated by an inner non-polarizing region,
providing a plurality of optical fibers insulated by ferrules,
inserting said plurality of optical fibers insulated by the ferrules into said holding device;
bonding said polarizing glass to said holding device and said plurality of optical fibers insulated by the ferrules,
forming an ultrathin polarizing glass by removing the second polarization layer and the non-polarizing region of the polarizing glass to expose the first polarization layer,
slicing the ultrathin polarizing glass at the ferrule interface to form a plurality of polarizer devices,
separating the polarizer devices attached to the optical fibers insulated by the ferrules from the surrounding ultrathin polarizing glass to form a plurality of vertically integrated optical components, and
removing said plurality of vertically integrated optical components from said holding device.
Each vertically integrated optical components comprises a polarizer device and an optical fiber insulated by a glass ferrule.
In a variation of the above described process the optical fibers are bonded to the polarizer devices subsequent to the slicing operation and removal of the parts from the holding device.
In another embodiment the process for making simultaneously a plurality of vertically integrated optical components comprising the steps of
providing a polarizing glass comprising a first polarization layer, a second polarization layer, and an inner non-polarizing region separating the first and the second polarization layers,
providing a glass substrate comprising a plurality of holes,
bonding the glass substrate to the polarizing glass,
providing a plurality of optical fibers equal to the number of holes in the glass substrate,
inserting the optical fibers in the holes,
bonding the optical fibers to the polarizing glass,
removing the second polarization layer and the non-polarizing region from the polarizing glass to expose the first polarization layer, such that an ultrathin polarizing glass is formed,
cutting the glass substrate and the ultrathin polarizing glass around each of the optical fibers to form a plurality of vertically integrated optical component.